Austin Exploration Inc., headquartered in Houston, Texas, conducts GPS-based high-resolution land and marine gravity and magnetic surveys throughout the world. Their surveys and associated interpretations have proven to be invaluable to the oil and gas industries worldwide. Austin Exploration’s surveys are also beneficial to the mining industry in its search for gold, silver, iron, zinc, lead and diamonds.

Austin Exploration has conducted nonexclusive regional land studies in the United States, beginning in the Cordilleran Hingeline Thrust Belt in Utah. Other nonexclusive areas of study include the Appalachian area, the Ouachita Trend in Arkansas, Oklahoma, Texas, Mississippi and Louisiana. Nonexclusive marine projects include most of the Gulf of Mexico and offshore Alaska, east and west coasts of North America, Sulawesi, Indonesia, Timor Sea and several surveys offshore United Kingdom.

Austin Exploration began their land survey operations in 1976, and in 1979 expanded their operations to include marine services. Shipboard systems have been employed in offshore South America, Africa, Pacific Rim countries, Europe, the coastal regions of North America, Indonesia, Malaysia, Korea, Vietnam and Burma.

Marine Surveys

To perform underwater gravity surveys and locate oil and gas beneath the floor of the ocean, Austin Exploration uses a ship equipped with advanced instrumentation to check below the ocean floor for minute differences in the earth’s gravitational field. These changes in the earth’s gravitational field indicate a change in density in the subsurface, and correspondingly, the presence of various structures including salt domes, anticlines (folds with layers of sedimentary rock sloping downward on both sides from a common crest), reefs, etc. By rigorously analyzing these changes in gravitational field, structures are precisely located implying the existence of oil fields.

Austin Exploration makes use of the most advanced marine surveying instrumentation including Digital Marine Gravity Meters and GPS Receivers, both with RS232 output. The marine gravity field meters are the latest in shipboard gravity technology manufactured by LaCoste and Romberg Laboratories, out of Austin, TX. The series 4000 GPS Receiver is manufactured by Trimble, from Sunnyvale, CA (800-827-8000, http://www.trimble.com). Since both instruments offer RS232 output, they are easily connected directly to a PC with a serial cable. Connecting the instruments to a PC offers complete automation of the survey data.

PC Configuration

The gravity information is recorded along with the GPS-based navigational information to accurately map density changes in the substructure beneath the ocean floor. To accomplish this the gravity information is fed into the PC over the PCs serial port 2 while a GPS Receiver is hooked up to serial port 3. The GPS Receiver accurately tracks the ship’s location relative to satellites in orbit around the earth.

Hence exact location and gravity information, from com 3 and com 2, must be simultaneously plotted into a Microsoft Excel spreadsheet. This is achieved using the WinWedge Pro from TALtech (800-722-6004, http://www.taltech.com). This software interfaces both the gravity meter and the GPS Receiver simultaneously and parses and filters the data and sends it to the correct locations in a Microsoft Excel (v7.0) spreadsheet. The spreadsheet then automatically graphs the information.

They are using an add-in 4 channel serial port board (Digiboard PC 4) by Digi International (800-344-4273) to allow for connection to additional serial ports.

Before they discovered WinWedge, researchers at Austin Exploration were using ProComm to simply dump the incoming serial data from the navigation equipment to a disk file. WinWedge allowed them more control over parsing, filtering and formatting their serial data and sending it in real time to their Excel spreadsheet. WinWedge also allowed them to collect data simultaneously from different instruments on different serial ports.

The digital marine gravity meters outputs binary serial data that is converted to decimal in the WinWedge before it is transferred to Excel. The GPS Receiver transmits serial ASCII data. As this is already decimal form, it can be easily transferred by WinWedge into Excel.

Conclusion

The results, which are collected in Excel in real time, help define subsurface structures believed to be prospective hydrocarbon accumulations (i.e. oil). Automating the collection of the survey data provides 100% accuracy and quality control of the data while at sea.